They're collecting dust in storage rooms and taking up extra space in your garage or office. They can't handle today's applications, peripherals or operating systems. Yes, older computers are a nuisGraphic: Diego Aguirreance, like the brother-in-law who sleeps on your sofa for a few months.

But tossing tech gear into the garbage is not exactly environmentally correct. Better ideas: Recycle older computers or retrofit them to serve a new purpose.

Luckily, older PCs and their kin are more than capable of handling a bunch of new uses; you can turn them into anything from gaming rigs to media stations where everyone in your family can rip CDs and fill up their MP3 players.

Here are my top 10 choices for what to do with a PC that's past its peak as a primary computing device but still has plenty of life in it for other uses. I've tried all of these, and I let you know how well these projects have worked for me. (And for another stroll down tech memory lane, check out "Vintage Video: 15 Funniest Tech Ads" and "The 25 Funniest Vintage Tech Ads.")

1. Use an old laptop as a guitar amp

One excellent use for an old computer is to re-imagine it as a guitar amp. You'll need an audio interface to connect a guitar to the computer, and you'll need used computer speakers. For my amp, I used a seven-year-old Apple iBook G3 that was loaded with OS X 10.4 (Tiger).

That older operating system could be a problem, because most of the newer apps that work as guitar amps -- including Native Instruments' Guitar Rig 4 Pro and the free version of Sonoma Wireworks' RiffWorks T4 -- require OS X 10.5 (Snow Leopard).

A Gibson electric guitar, a Cakewalk UA-1G audio interface, Reaper software and an old iBook combine to create a great guitar amp.

I ended up using Cockos Inc.'s Reaper because it's shareware; you can buy it for $60 after 30 days ($225 for the full commercial version). It works well on older Macs because it's a light app that doesn't use all of the latest bells and whistles of the Mac OS Core Audio components. The software has guitar distortion sounds, delays and grungy hard rock settings.

Now that I had my amp, I needed an audio interface. I already had a Cakewalk UA-1G, which is a slimline device with just one volume button, a quarter-inch port for the guitar and an attached USB cable. The driver for the UA-1G worked great with the iBook 3G running OS X 10.4. I connected a pair of powered speakers and brought my iBook back from the dead, ready to rock.

Interestingly, the sound quality on this older iBook was still quite amazing, mostly because it's not necessarily the Mac that's generating the sound -- your computer becomes a fancy controller for the audio interface. In fact, quality (and the all-important power output) depends more on the speakers you use. I used a pair of Boston Acoustics RS 334 floorstanding speakers that sounded outstanding.

2. Use an old notebook as an e-mail terminal

With some older laptops, the trick is where you set up the system and not necessarily whether it's fast enough for every computing activity. For example, I used a five-year-old Toshiba Satellite 4600 to set up Yahoo Mail in full-screen mode (in Internet Explorer, just press F11). I then placed the computer in a hallway where any member of my family or a visiting friend can jump on it to check for messages.

Use an old laptop as an e-mail terminal; you can run the browser in full-screen mode by pressing F11 so that it hides other applications and options.Granted, this terminal is not adequate for anything beyond basic Web browsing and e-mail, but it's only a click away for those who just need to write a quick note or update their Facebook or Twitter status.

The old Toshiba laptop is not fast enough for any other computing activities, but it has a bright screen and the keyboard works well (minus one missing function key). Because I keep just my e-mail up on the screen with no other apps running, this sluggish laptop works just fine for typing up e-mail replies, even if you can't use other apps.